Compression Test

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skillz2k5

Senior Member
So I went and got the gauge set from orielly's today and checked my compression. I did it three ways because I was getting funky readings the first two times.

The first time I checked it was with all the plugs in except the cylinder I was checking compression on (obviously) and with the fi/em fuse still in. The results were::

D
120
120
130
120
T

The second time I checked all the plugs were in but with the fi/em fuse pulled. The results were:

D
170
170
180
170
T

The third time was with plugs out and fuse out. Also I cranked the car untill the needle on the gauge stopped building (I was figuring this was the correct way to go about it). The results were:

D
215
215
220
215
T

Does the third method/numbers seem correct for a b series vtec motor?? Jdm B16 to be exact. Also I have heard that differences in the numbers isn't a good sign. What would cause a slight change from cylinder to cylinder. Also the D signafies dizzy side and T signafies timing belt side... for those that have no common sense :D
 
It is very rare to get the same number all across the board. Your numbers are beautiful. Nice and healthy.
 
I know you don't have a problem with those numbers.
---CLEAN BILL OF HEALTH---
 
cashen said:
Difference in compression is usually a headgasket or rings problem. Here's the write up from the tech articles. I'd just quote it but I don't know how to do that. I don't think you have a problem with yours being so close together though.
https://hondaswap.com/general-tech-articles/how-leak-down-compression-tests-29104/

Difference in compression doesn't mean any of those are bad. you can have up to a 15%-20% diflection in compression and the engine will be running perfectly fine.
 
The throttle open?? I never thought of that... would this make any difference?
Thanks for all the replys to this but I'm not really looking for advise in the numbers
more or less just the method in which it was done with the corresponding numbers.
 
of course it would, lol
the throttle body being open = no air restriction
you would get your peak reading faster, but since you let it spin until it the needle stopped moving then it would all be the same in the end...
 
ic ic... fortunatley never had the need/want to run a comp test before this so just wanted to make sure everything was done correctly. Thanks for all the help guys!
 
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